1. Field of the Disclosure
The inventive concepts disclosed herein relate to cooling towers, and more particularly, but not by way of limitation, to a modular concrete induced draft water cooling tower capable of being constructed substantially on site.
2. Brief Description of Related Art
Counterflow water cooling towers traditionally have been of three types, namely forced draft, natural draft, and induced draft. Forced draft towers have fans located on the sides below the fill material with air turning vanes or they may have fans situated directly below the fill material with a water/air separation system. An example of a forced draft counterflow cooling tower is disclosed in U.S. Pat. No. 5,545,356, which is hereby expressly incorporated herein by reference.
Natural draft counterflow cooling towers are utilized in many large coal or nuclear power plants and they do not use a fan to assist the air flow, but instead rely upon the natural tendency of less dense, warmer air to flow upward from lower level side openings to a less dense environment at the top. Although savings in electric usage are experienced, the upfront cost of construction of these extremely tall hyperbolic natural draft concrete towers is significant, and thus prohibitive in many instances.
An induced draft counter flow cooling tower has a fan located on top of the tower which draws air upward through a fill material. Air flows laterally along the ground surface adjacent to the tower module(s) and once in the tower, the air turns ninety degrees or greater and flows upward through the fill material. At the same time, the air flows upward through the fill material, water flows downward through the fill material under the force of gravity, hence the title “counterflow” in that the air and the water are moving in opposite directions.
Another common type of cooling tower is a cross flow tower. These cross flow cooling towers are usually induced draft towers which have a plenum chamber and fan located on top of the tower pulling the air up through the tower. Cross flow cooling towers have the warmer water falling downward through fill material while cooling air is drawn in horizontally at approximately ninety degrees to the path of the falling water. This requires specialized fill to achieve optimal results.
Typically industrial cooling towers are large structures having footprint dimensions on the order of forty feet to as much as six hundred feet and having a height on the order of twenty to thirty feet. The construction of such a large tower is a major undertaking, with the delay between the time of order and the time of complete construction and on-line operation being on the order of one year minimum.
Common cooling tower construction utilizes either top mounted fans with wood framed or cast-in-place concrete for large towers. Fiberglass-reinforced plastic (hereinafter referred to as “FRP”) or sheet metal, or combinations of these, are used for small towers manufactured in a plant and transported generally by truck to the project location. Other construction methods may comprise precast construction with an elevated trough system for water collection with a bottom mounted fan and no ground level basin below the tower. These structures have in the past been typically constructed of wood. However, wood structures typically have a limited life span and significant maintenance requirements due to wood deterioration in a water environment. Although there are instances of concrete cooling towers, these have typically been custom designed cast-in-place towers that are very expensive to build, and have pumping height requirements similar to the wood towers, which is a major drawback due to the overall configuration and height.
Accordingly, a need exists for a cooling tower capable of being constructed substantially on site, which is inexpensive to build, durable, and capable of modular expansion. It is to such an apparatus and method that the inventive concepts disclosed herein are directed.